GENERAL DESCRIPTION

The AD7376 provides a single channel, 128-position digitally controlled variable resistor (VR) device. This device performs the same electronic adjustment function as a potentiometer or variable resistor. These products were optimized for instrument and test equipment applications where a combination of high voltage with a choice between bandwidth or power dissipation are available as a result of the wide selection of end-to-end terminal resistance values. The AD7376 contains a fixed resistor with a wiper contact that taps the fixed resistor value at a point determined by a digital code loaded into the SPI-compatible serial-input register. The resistance between the wiper and either endpoint of the fixed resistor varies linearly with respect to the digital code transferred into the VR latch. The variable resistor offers a completely programmable value of resistance between the A terminal and the wiper or the B terminal and the wiper. The fixed A to B terminal resistance of 10 k?, 50 k?, 100 k? or 1 M? has a nominal temperature coefficient of –300 ppm/°C.

FEATURES

128 Position

Potentiometer Replacement

10 kΩ, 50 kΩ, 100 kΩ, 1 MΩ

Power Shutdown: Less than 1 μA

3-Wire SPI Compatible Serial Data Input

+5 V to +30 V Single Supply Operation

±5 V to ±15 V Dual Supply Operation

Midscale Preset

APPLICATIONS

Mechanical Potentiometer Replacement

Instrumentation: Gain, Offset Adjustment

Programmable Voltage-to-Current Conversion

Programmable Filters, Delays, Time Constants

Line Impedance Matching

Power Supply Adjustment